Buggy code:
public class Main implements ProblemSeverities , SuffixConstants { public static class Logger { PrintWriter out ; PrintWriter err ; PrintWriter log ; public Logger ( PrintWriter out , PrintWriter err ) { } public void setLog ( PrintWriter log ) { } public void close ( ) { <START_BUG> if ( ( log ) != null ) { <END_BUG> this . log . close ( ) ; } } public void flush ( ) { } public void printErr ( String s ) { } public void printlnErr ( String s ) { } public void printlnOut ( String s ) { } public void printlnOut ( ) { } public void printOut ( char c ) { } } public static ResourceBundle bundle ; public static final String bundleName = "org.eclipse.jdt.internal.compiler.batch.messages" ; public static final char [ ] DOUBLE_QUOTES = "''" . toCharArray ( ) ; public static final char [ ] SINGLE_QUOTE = "'" . toCharArray ( ) ; public String [ ] classpaths ; public String destinationPath ; public String [ ] encodings ; public Main . Logger logger ; public int exportedClassFilesCounter ; public String [ ] filenames ; public boolean generatePackagesStructure ; public int globalErrorsCount ; public int globalProblemsCount ; public int globalWarningsCount ; public long lineCount ; public String log ; public boolean noWarn = false ; public Map options ; public CompilerOptions compilerOptions ; public boolean proceed = true ; public boolean proceedOnError = false ; public boolean produceRefInfo = false ; public int repetitions ; public int maxProblems ; public boolean showProgress = false ; public boolean systemExitWhenFinished = true ; public long startTime ; public boolean timing = false ; public boolean verbose = false ; public Main ( PrintWriter outWriter , PrintWriter errWriter , boolean systemExitWhenFinished ) { } public Main ( PrintWriter outWriter , PrintWriter errWriter , boolean systemExitWhenFinished , Map customDefaultOptions ) { } public static String bind ( String id ) { } public static String bind ( String id , String binding ) { } public static String bind ( String id , String binding1 , String binding2 ) { } public static String bind ( String id , String [ ] bindings ) { } public static boolean compile ( String commandLine ) { } public static boolean compile ( String commandLine , PrintWriter outWriter , PrintWriter errWriter ) { } public static void main ( String [ ] argv ) { } public static void relocalize ( ) { } public static String [ ] tokenize ( String commandLine ) { } public boolean compile ( String [ ] argv ) { } public void configure ( String [ ] argv ) throws InvalidInputException { } private void disableWarnings ( ) { } public String extractDestinationPathFromSourceFile ( CompilationResult result ) { } public ICompilerRequestor getBatchRequestor ( ) { } public CompilationUnit [ ] getCompilationUnits ( ) throws InvalidInputException { } private File [ ] [ ] getLibrariesFiles ( File [ ] files ) { } private int getLength ( File [ ] [ ] libraries ) { } public IErrorHandlingPolicy getHandlingPolicy ( ) { } public FileSystem getLibraryAccess ( ) { } public IProblemFactory getProblemFactory ( ) { } public void outputClassFiles ( CompilationResult unitResult ) { } public void performCompilation ( ) throws InvalidInputException { } public void printStats ( ) { } public void printUsage ( ) { } public void printVersion ( ) { } }

Fix:
if ( ( this . log ) != null ) {